A young maths genius sees logic thwarted by one truly baffling equation: love. Teenage maths prodigy Nathan (Asa Butterfield) struggles when it comes to building relationships with other people, not least with his mother, Julie (Sally Hawkins). Nathan is taken under the wing of his unconventional teacher Mr. Humphreys (Rafe Spall) and pair forge an unusual friendship. 

Eventually, Nathan’s talents win him a place on the UK National team at an international mathematics tournament in Taiwan. In unfamiliar surroundings Nathan is confronted by a series of unexpected challenges, not least the unfamiliar feelings he begins to experience for his Chinese counterpart, the beautiful Zhang Mei (Jo Yang).